1. Field of the Invention
This invention relates to a mounting arrangement for supporting a flexible sound generating diaphragm and, more particularly, to an arrangement for positioning and supporting a piezoelectric driven diaphragm on a node ring.
2. Description of the Prior Art
Piezoelectric transducers driven by a small disc of piezoceramic material bonded to a thin metal diaphragm are well known. When an appropriate electrical signal is applied to the disc, the disc changes its diameter, causing the composite structure of the piezoceramic disc and the metal diaphragm to flex accordingly from a flat shape into either a convex or concave shape. As the polarity of the electrical input signal changes, the shape of the flexible diaphragm also changes. By varying the polarity of the input signal at a particular frequency, the flexible diaphragm can be made to vibrate at the same frequency. To produce sound, some portion of the flexible diaphragm must be mounted to a fixed surface. This is typically accomplished by securing the diaphragm to an annular support surface by means of clamping or gluing. For loud sound, it is common to mount the diaphragm on a node ring of the diaphragm for the particular exciting frequency. The prior art mounting arrangements typically require careful alignment of the diaphragm and the support elements in order to assure that the diaphragm is secured on the desired node ring. In many instances the diaphragm is attached to the support member by a rubber-like cement which requires a period of time for curing.